Cardio: Anti-Arrhythmias

SA node

What part of the heart initiates the heartbeat normally in a healthy person?

SA node

What part of the heart is the pacemaker?

AV node

Which part of the heart is the gatekeeper

SA node > Right Atria or Left Atria > AV node > Bundle of HIS > Branches > Purkinjie fibers

How does the electrical impulse travel in the heart

Right atrium

Where is the SA node located in the heart?

60-100

How much electric impulse can SA node generate

Depolarization/ Contraction

If electric impulse from SA node reaches the left/right atrium what happens?

0.1 seconds

How much seconds is the delay of AV node?

Allows sufficient time to fill ventricle with blood from atrium

Why is there a gatekeeper, what is its purpose

• Apex

• Purkinjie fibers

The ventricles contract starting from the ___ to the ___

• Non-pacemaker cells

• Pacemaker cells

2 types of cardiac action potential

Membrane potential

Cardiac action potential is also known as?

Membrane potential

Different charges in two locations in the membrane, what is it termed as?

Action potential

Is the rapid change of electrical voltage in the membrane is termed as?

Non-pacemaker cells

Which two types of cardiac action potential that do not initiator the action potential?

Do not initiate the Action potential

In a normal condition, non-pacemaker cells normally do what?

• Atria

• Ventricles

• Purkinjie fibers

Examples of non-pacemaker cells

5 phases

How many phases are within a non-pacemaker cell?

-90 millivolts

How many millivolts are there in the 4th phase of the non-pacemaker cells?

Phase 4

What phase is considered as the resting membrane potential?

Phase 4

What phase is a negative membrane potential

• Due to K+ equilibrium potential

• Potassium efflux

how does phase 4 happen in the non-pacemaker cell?

Phase 0

What phase is where the purkinjie fibers receive the action potential

• -90

• +20

In phase 0, the charge will go up from ___ to ___ in the non-pacemaker cell

Phase 0

Phase that is called fast depolarization?

Na+

What ion is responsible in phase 0 that shoot up from negative to positive mv in non-pacemaker cell

• Phase 4

• Phase 0

• Phase 1

• Phase 2

• Phase 3

Order of phases in Non-pacemaker cells

Phase 1

Phase that has a brief initial repolarization

Phase 1

Which phase does Na channels closes

Potassium channels

When Na channels close in Phase 1, what channels open?

Phase 1

Phase that is called the early fast repolarization

Phase 2

What phase is refer to as the Plateau

Phase 2

Phase that has a balance movements of the ff. ions:

• Potassium

• Calcium

Phase 3

What phaseL From 0 to -90 mv

Repolarization

What occurs in phase 3?

Calcium channel

What channels close in the phase 3?

Potassium channel

What channel remains open in phase 3?

SA node

Examples of pacemaker cells

• Phase 4

• Phase 0

• Phase 3

How many phases does pacemaker cell have?

• Phase 2

• Phase 1

What phases are not present in the pacemaker cells

• Becomes less negative as before (kusang tumataas ang membrane potential)

• Opening of Sodium funny channels

What happens in phase 4 of pacemaker cells

Threshold potential

It is the minimum requirement to fire an electric current in the context of pacemaker cardiac action potential

Phase 4

What phase of pacemaker cells where it rises from -60 to threshold potential

Automaticity

Ability of generating its own action potential of SA node

-40 mv

Minimum requirement mv to generate action potential in pacemaker cells

steeped

Which one would reach action potential in pacemaker cells in phase 4. steep or sloped

Calcium

What ion is responsible for the action potential in pacemaker cells?

• Non-pacemaker cells: Sodium

• Pacemaker cells: Calcium

Difference between Non-pacemaker cells and pacemaker cells in generating action potential

Electrical tissue

What tissue is classified for pacemaker cells

Contractile tissue

What tissue is classified for non-pacemaker cells

• Ca channels closes

• K+ channels opens

What channel opens and closes in phase 3 of pacemaker cells

Phase 4

What phase in pacemaker cells is considered as the unstable resting membrane potential

Automaticity

What term refers to the spontaneous depolarization

• Calcium

• Going in

What ions are responsible for phase 0 of pacemaker cells, and is it going in or out of the cell?

• Phase 4: unstable resting membrane potential

• Phase 0: Ca+ conductance

• Phase 3: Repolarization

Describe each phase in pacemaker cells